Is there a minimalist WebSocket client library for java?

Question

The title says it all.

I'm trying to make a video game that connects to a server hosted on heroku for file verification.

Since heroku doesn't support vinella sockets I have to use websockets. I can make a websocket server just fine with Ruby or with some big java framework but I can't find a lightweight solution for making a client socket with java.

Thanks in advance!

score 4 · Answer 1 · answered Mar 12 '14 at 08:53

JSR 356 (Java API for WebSocket), part of Java EE 7 defines client API. There are multiple implementations: Tyrus (glassfish/WLS), Tomcat, ...; basically every container do provide the implementation or this api, even if not implementing other Java EE 7 specifications.

Simple example:

        final WebSocketContainer client = ContainerProvider.getWebSocketContainer();
        final Session session = client.connectToServer(new Endpoint() {
            @Override
            public void onOpen(Session session, EndpointConfig EndpointConfig) {

                try {
                    session.addMessageHandler(new MessageHandler.Whole<String>() {
                        @Override
                        public void onMessage(String message) {
                            System.out.println("### Received: " + message);
                        }
                    });

                    session.getBasicRemote().sendText("Do or do not, there is no try.");
                } catch (IOException e) {
                    // do nothing
                }
            }

            @Override
            public void onClose(Session session, CloseReason closeReason) {
                System.out.println("### Client session closed: " + closeReason);
            }
        }, ClientEndpointConfig.Builder.create().build(), URI.create("ws://echo.websocket.org"));

You can check Client Endpoint chapter in Tyrus user guide for more details.

Tyrus is in a bad state. It's transitioning into Eclipse and is currently in incubation. I've come across an issue where Tyrus will terminate a connection failing to accept a server side handshake on a wss socket, this issue only showing in some last mile networks and not others. I'd recommend using the Jetty implementation and NOT using it through javax.websocket, but using Jetty's API surface instead (as javax.websocket does not allow to set the default max message size properties in Jetty). — Tobias, Aug 02 '18 at 01:09

score 1 · Accepted Answer · answered Mar 12 '14 at 01:26

1

Jetty has WebSocket Client API

Jetty WebSocket Client API

answered Mar 12 '14 at 01:26

Dongho Yoo

1,506
16
16

score 0 · Answer 3 · answered May 04 '22 at 17:15

Just for completeness in future search hits, JavaSE 11 now has WebSocket support as well, in the java.net.http package.

Although I confess I'm finding only basic documentation and simplistic examples so far. Which leaves a bit to be desired in implementing a complete, robust solution. Among other things, a decent understanding of Java Concurrency seems to be required.

There's a little bit here: Require assistance with simple pure Java 11 WebSocket client example

Is there a minimalist WebSocket client library for java?

3 Answers3